Clinical implication of Frizzled 2 expression and its association with epithelial-to-mesenchymal transition in hepatocellular carcinomaClinical implication of Frizzled 2 expression and its association with epithelial-to-mesenchymal transition in hepatocellular carcinoma肝細胞癌におけるFrizzled 2発現の臨床的意義と上皮間葉転換との関連